How does concentration affect the rate of reaction?

It's like rugby 7s and 15s

Rugby 7s has only 7 players from each each team playing, so the game is mostly centered about dodging with the ball and there is a lesser chance of getting tackled. Rugby 15s on the other hand, has the same field, but more people in the field, instead of 7, it's 15 from each side. Now there is a high possibility of getting tackled if you have the ball.

metric time was an attempt to create a standard unit of time based off of 10, but it never took off an is not included in the metric system (si)

the correct answer would be b) volume versus temperature, because they are also directly proportional.